From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:6f8:1178:4:290:27ff:fe1d:cc33]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1Sm7Vl-0006sB-R4 for barebox@lists.infradead.org; Tue, 03 Jul 2012 18:07:43 +0000 From: Sascha Hauer Date: Tue, 3 Jul 2012 20:07:37 +0200 Message-Id: <1341338857-29138-1-git-send-email-s.hauer@pengutronix.de> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: barebox-bounces@lists.infradead.org Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: [PATCH] fs: fix standard zero, full devices To: barebox@lists.infradead.org The standard devices are currently broken since they have the size ~0. As now files use loff_t as file size which is a signed type the read implementation gets confused and now returns -1. The current implementation also has the (somewhat theorical) problem that we do not have real streaming devices, so /dev/zero went out of zeroes after reading 4GB (or now LLONG_MAX). This patch introduces a new cdev flag DEVFS_IS_CHARACTER_DEV and a new file size flag FILE_SIZE_STREAM which makes it possible to create real stream devices instead. Signed-off-by: Sascha Hauer --- commands/stddev.c | 6 +++--- fs/devfs.c | 3 ++- fs/fs.c | 8 ++++---- include/driver.h | 1 + include/fs.h | 1 + 5 files changed, 11 insertions(+), 8 deletions(-) diff --git a/commands/stddev.c b/commands/stddev.c index 97080eb..098aea8 100644 --- a/commands/stddev.c +++ b/commands/stddev.c @@ -40,7 +40,7 @@ static int zero_init(void) cdev = xzalloc(sizeof (*cdev)); cdev->name = "zero"; - cdev->size = ~0; + cdev->flags = DEVFS_IS_CHARACTER_DEV; cdev->ops = &zeroops; devfs_create(cdev); @@ -68,7 +68,7 @@ static int full_init(void) cdev = xzalloc(sizeof (*cdev)); cdev->name = "full"; - cdev->size = ~0; + cdev->flags = DEVFS_IS_CHARACTER_DEV; cdev->ops = &fullops; devfs_create(cdev); @@ -95,7 +95,7 @@ static int null_init(void) cdev = xzalloc(sizeof (*cdev)); cdev->name = "null"; - cdev->size = 0; + cdev->flags = DEVFS_IS_CHARACTER_DEV; cdev->ops = &nullops; devfs_create(cdev); diff --git a/fs/devfs.c b/fs/devfs.c index ea8b250..fccf25a 100644 --- a/fs/devfs.c +++ b/fs/devfs.c @@ -121,7 +121,8 @@ static int devfs_open(struct device_d *_dev, FILE *f, const char *filename) if (!cdev) return -ENOENT; - f->size = cdev->size; + f->size = cdev->flags & DEVFS_IS_CHARACTER_DEV ? + FILE_SIZE_STREAM : cdev->size; f->inode = cdev; if (cdev->ops->open) { diff --git a/fs/fs.c b/fs/fs.c index 1774fb7..0b376a5 100644 --- a/fs/fs.c +++ b/fs/fs.c @@ -643,7 +643,7 @@ int read(int fd, void *buf, size_t count) fsdrv = dev_to_fs_driver(dev); - if (f->pos + count > f->size) + if (f->size != FILE_SIZE_STREAM && f->pos + count > f->size) count = f->size - f->pos; if (!count) @@ -672,7 +672,7 @@ ssize_t write(int fd, const void *buf, size_t count) dev = f->dev; fsdrv = dev_to_fs_driver(dev); - if (f->pos + count > f->size) { + if (f->size != FILE_SIZE_STREAM && f->pos + count > f->size) { ret = fsdrv->truncate(dev, f, f->pos + count); if (ret) { if (ret != -ENOSPC) @@ -740,12 +740,12 @@ loff_t lseek(int fildes, loff_t offset, int whence) switch (whence) { case SEEK_SET: - if (offset > f->size) + if (f->size != FILE_SIZE_STREAM && offset > f->size) goto out; pos = offset; break; case SEEK_CUR: - if (offset + f->pos > f->size) + if (f->size != FILE_SIZE_STREAM && offset + f->pos > f->size) goto out; pos = f->pos + offset; break; diff --git a/include/driver.h b/include/driver.h index a5e3f44..7d597b4 100644 --- a/include/driver.h +++ b/include/driver.h @@ -417,6 +417,7 @@ int cdev_erase(struct cdev *cdev, size_t count, loff_t offset); #define DEVFS_PARTITION_FIXED (1 << 0) #define DEVFS_PARTITION_READONLY (1 << 1) #define DEVFS_IS_PARTITION (1 << 2) +#define DEVFS_IS_CHARACTER_DEV (1 << 3) int devfs_add_partition(const char *devname, loff_t offset, loff_t size, int flags, const char *name); diff --git a/include/fs.h b/include/fs.h index 2b1023e..c0b9f71 100644 --- a/include/fs.h +++ b/include/fs.h @@ -24,6 +24,7 @@ typedef struct dir { typedef struct filep { struct device_d *dev; /* The device this FILE belongs to */ loff_t pos; /* current position in stream */ +#define FILE_SIZE_STREAM ((loff_t) -1) loff_t size; /* The size of this inode */ ulong flags; /* the O_* flags from open */ -- 1.7.10 _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox